I suspect that people who have somewhat older Macs (obviously there's some limit) who find their web browsing intolerably slow probably have something else going on with either their install or their network.
This makes me call into question literally everything else in your post.
You might be able to do CPU based for a few trials for fun, but you arent running LLMs on CPU on a daily basis.
The relatively little LLM use I do is in a browser and it doesn't matter which computer I'm doing it on.
So sad this kind of shenanigans are not possible anymore.
It didn't look like a good candidate for OpenCore Legacy because of the dual video cards, but it feels so gross recycling a perfectly working computer.
I find that a lot of my work is "remote" at this point. Im doing most things on Servers, VM's, and containers on other boxes. The few apps that I do run locally are suffering (browser being the big offender).
Is most of what you're doing remote? Do you have a decent amount of ram in that air?
I still have the air with whatever the macos is, but as soon as i have a minute i'm going to try and get linux or BSD on it. I'm still sore at how little use i got out of that machine - and i got it "open box" "scratch and dent", so it was around $500 with tax. I got triple the usage out of a 2009ish eeePC (netbook)